If your company develops or verifies software for the avionics industry, you are probably familiar with DO-178C Software Considerations in Airborne Systems and Equipment Certification.

In brief, DO-178C is a document published by RTCA and used by the Federal Aviation Agency (FAA) as the main guidance to determine if the software will perform safely and reliably in an airborne environment. DO-178C lists a series of objectives that need to be accomplished in order to produce reliable software according to the impact in safety caused by a failure condition of that software.

The FAA has established a software audit process that ensures compliance to the DO-178C objectives and other applicable software policy, guidance, and issue papers. This audit process includes four Stages of Involvement (SOI) throughout the software life cycle of a project:

Planning Review

Development Review

Verification Review

Final Review

The intent of this article is not to explain each SOI, but to assist you in being successful when the FAA’s Designated Engineering Representative (DER) or delegate performs an audit of your software project. For more information on the software audit process you may read the FAA Order 8110.49, Software Approval Guidelines available on the FAA website.

Companies are oftentimes exposed to audits which may be stressful, but they do not have to be that way. The following guidelines will help you handle FAA auditors, avoid common mistakes and reduce or even eliminate stress.

1. Plan the Audit

Preparation is the key to having a successful audit.

It is important to schedule a meeting with the DER well before the audit to discuss the topics that will be addressed during the visit. Ask the DER questions like:

What is the scope of the audit?

What documentation and materials will be needed and how soon?

When will the audit occur?

How long will it take to complete the audit?

What support and considerations will be required (e.g., workspace, Internet access, and projector)?

What to do if you are not ready: It is extremely important that you are ready before the DER’s visit. If you are not ready, consider postponing the visit for a date when you will be ready. Why? Because neither you nor the DER will be very happy afterward when you both conclude that the audit has to be rescheduled, wasting the DER’s time and your company’s money. If you haven’t worked with the DER before, you may want to provide documentation in advance to confirm that you are ready, just to be safe.

Before you start, you should know what Level of Involvement (LOFI) the DER or designee will maintain with your facility. You can estimate/calculate their LOFI using a checklist that is available in the FAA 8110.49 Software Approval Guidelines.

The checklist provides a result that basically tells the DER what degree of thoroughness should be maintained during the software audit. There are three types of Involvement: Low, Medium and High. For example, for a Low level, the DER may want to check artifacts via e-mail or through a web based system. In the other extreme, for a High level, the DER will do on-site audits for every step of the project. This checklist is normally completed in advance by the DER but it is important that you are familiar with it and prepared to provide the information that the DER may request to complete it. Your initiative may help to build up the level of comfort of the DER by showing that you have been through the process before.

2. Build Your Team

Having the right people available to support the software audit is critical. A team that includes representatives from Project Management, Development, Verification and Quality Assurance will be more than adequate. People who either have the answers at hand or can quickly investigate issues and report back to the DER can help move a software audit along faster.

Before the software audit, it is important to designate a main speaker for the meeting so that he/she can decide who should answer which questions from the DER. Typically the Project Manager should be the main speaker of the meeting; but it could be anyone with sufficient knowledge of the project, process and team members’ capabilities. Not all the team members have to be present at all times, however the Quality Assurance and Project Management team members should be present.

3. Conduct a Self Assessment

Ask your Quality Assurance team member to lead a company self-assessment well in advance of the actual audit. The checklists that the DER will most likely use to perform the audit are contained in the Conducting Software Reviews Job Aid document available for download at the FAA website. Your team should select the checklists and checklist items that are most appropriate depending of the software level and the SOI that is being reviewed.

Evidence should be provided for each response of a checklist item. Do not resort to just giving “Yes” or “No” statements. Answers should be justified with objective evidence (e.g., document references, record references, justifications).

Some DERs will request more than one piece of evidence for each checklist item, so be sure to discuss this with the DER before you start the self-assessment. If you are not sure how to address a specific checklist item, don’t hesitate to ask the DER; you do not want to be at the audit without knowing what is expected from you.